We have changed the vinyl through out our older Maramu. it is a messy process but doable. There are other posts here on how to do it. However, there are two issues. in some areas, especially the ceiling of the forward cabin and the salon, the fiberglass surface is irregular and not thick, therefore it is translucent. So if you paint or glue the vinyl directly, you will have an uneven surface and maybe see some light in the daytime. We used a floating system to avoid gluing the vinyl directly, except in areas like bulkheads, heads and vertical surfaces in general.
Good luck if you decide to go ahead with this project.
Maramu #94, 1981